The **MDA-5-R** is a specific type of **Time-Delay (Slo-Blo) Fuse** manufactured by Bussmann (now part of Eaton). It is part of the MDA series, which is widely used in power supplies and industrial equipment to handle temporary current surges without blowing prematurely. ### Technical Specifications Below are the primary electronic characteristics of the MDA-5-R: | Specification | Value | | :--- | :--- | | **Current Rating** | 5 Amperes | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Ceramic Tube (Time-Delay) | | **Physical Size** | 1/4" x 1-1/4" (6.3mm x 32mm) | | **Termination Style** | Cartridge / Ferrule | | **Interrupt Rating** | 1500A @ 250VAC | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### Key Component Features #### 1. Ceramic Construction Unlike glass fuses, the MDA series uses a **ceramic tube**. Ceramic is structurally stronger and can handle higher internal pressures and temperatures. This allows the fuse to have a much higher "interrupting rating," meaning it can safely break a circuit during a high-energy short circuit without the casing shattering. #### 2. Time-Delay (Slo-Blo) Functionality The MDA-5-R is designed to ignore short-duration "inrush currents." For example, when a motor starts or a large capacitor charges, the current might momentarily spike above 5A. * **Action:** It will hold for a specific duration at over-current before melting. * **Purpose:** Prevents "nuisance blowing" in inductive or capacitive loads. #### 3. The "-R" Suffix The suffix specifically denotes that the part is **Lead-Free and RoHS compliant**. This is critical for modern manufacturing standards and environmental regulations. --- ### Comparison with Glass Fuses (MDL Series) | Feature | MDA Series (Ceramic) | MDL Series (Glass) | | :--- | :--- | :--- | | **Visibility** | Opaque (cannot see wire) | Transparent (can see wire) | | **Interrupt Rating** | High (1500A+) | Low (approx 35A - 200A) | | **Typical Use** | Industrial/Heavy Duty | Consumer Electronics | --- ### Common Applications * **Power Supplies:** Protecting the input stage of AC/DC converters. * **Industrial Control Panels:** Where vibration or high heat might affect glass fuses. * **Motor Circuits:** Handling the startup surge of small motors.